KR20180122825A - Powder Press Machine Having Servomotor Driving Mechanism - Google Patents

Abstract

The present invention relates to a servo motor driven powder molding press apparatus capable of being moved up and down by using a die provided with a punch for pressing powder or a molding hole into which a powder material is inserted by a ball screw directly connected to a servo motor and the servo motor. The servo motor driven powder molding press apparatus according to the present invention comprises: the servo motor fixed to an upper portion or a lower portion of a press apparatus main body; a ball screw including a screw shaft having one end rotationally coupled to the center of the servo motor and having a screw groove formed in a spiral shape on the outer surface thereof, and a nut unit which is spirally coupled to the outer surface of the screw shaft (121) and moves up and down in the axial direction of the screw shaft by rotation of the screw shaft as the screw shaft rotates; and a ram coupled to an outer side of the nut unit and moving up and down together with the nut unit, and having a punch for pressing the powder material at one end unit or the die into which the powder material is introduced.

Description

[0001] Powder Press Machine Having Servomotor Driving Mechanism [

More particularly, the present invention relates to a press apparatus for powder molding, and more particularly, to a die for press molding powder or a die having a molding hole into which powder material is input by a servo motor and a ball screw directly connected to a hollow portion of the center of the servo motor The present invention relates to a press machine for powder molding having a servomotor drive device which can be moved up and down by using a motor.

Powder molding is a molding method in which a powder material such as a metal powder is filled into a die cavity and compression molded by an upper punch and a lower punch to produce a powder compact of a green compact of a desired shape and shape, The present invention relates to a molding method capable of easily molding a product which is difficult to work in a molding machine,

Such powder molding is performed by a powder molding press apparatus, and a conventional powder molding press apparatus uses a hydraulic cylinder to drive the upper punch and the lower punch up and down to pressurize the powder material.

However, when the upper punch and the lower punch are driven to press the powder by using the hydraulic cylinder, since the hydraulic pressure is greatly influenced by the environment such as the temperature, the upper punch and the lower punch are precisely There is a problem that it is difficult to control, and therefore there is a limit to the precision such as the dimensions and density of powder molded articles.

Registration No. 10-1258664 (Registered on April 22, 2013) Registration Utility Model No. 20-0251129 (Registered on October 10, 2001) Registration No. 10-0157526 (registered July 30, 1998)

It is an object of the present invention to accurately control the speed and stroke of a punch and a die by driving a punch or a die up and down using a servomotor, Which is capable of improving the dimensional and shape accuracy of the powder molded product through the use of the above-mentioned powder molding machine.

According to an aspect of the present invention, there is provided a servo-motor-driven powder molding press apparatus comprising: a main body; A die installed in the body so as to be movable up and down, and having a molding hole through which the powder material to be molded is inserted; A lower punch fixed to the main body at a lower side of the die and inserted through a lower portion of the die; An upper punch disposed above the die and movable upward and downward to press the powder material together with the lower punch while being inserted through an upper portion of a molding hole of the die; A punch driving unit and a die driving unit installed at the upper and lower portions of the main body to move the upper punch and the die up and down; And a powder supply unit for supplying the powder material to the inside of the die cavity of the die, wherein the punch driver and the die driver include: a servo motor fixed to each of the upper and lower portions of the main body; A screw shaft rotatably coupled to the center of the servomotor and having a screw groove formed in a spiral shape on an outer surface thereof; a screw shaft coupled to an outer surface of the screw shaft so as to be rotated in the axial direction of the screw shaft A ball screw having a nut portion moving upward and downward along a vertical direction; And a ram coupled to an outer side of the nut to move up and down together with the nut and to which a punch for pressing the powder material at one end or a die into which the powder material is inserted is combined.

According to the present invention, since the servomotor and the ball screw coupled to the center of the servo motor are used as the punch or die driving device of the press apparatus, the speed and distance control of the punch and die can be very precise, The dimensional accuracy and shape accuracy of the molded article can be greatly improved.

Particularly, the rotor of the servomotor constituting the driving device of the press apparatus of the present invention is formed of a hollow body having an empty central portion, and the screw shaft of the ball screw is inserted into the hollow portion of the rotor to be engaged. So that the upper punch or die can be moved up and down, so that the operation of the ball screw can be controlled more precisely.

1 is a front view of a section of a press apparatus for powder molding according to an embodiment of the present invention.
Fig. 2 is a front view of the powder press apparatus shown in Fig. 1. Fig.
3 is a cross-sectional view showing a configuration of a punch driving unit of the powder molding press apparatus shown in Fig.
4 is a front view showing a ball screw of the punch driving unit shown in FIG.
Fig. 5 is a cross-sectional view showing the configuration of the die drive unit of the powder molding press apparatus shown in Fig. 1;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a servo motor-driven powder molding press apparatus according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 to 5 show an embodiment of a powder molding press apparatus to which the drive apparatus of the present invention is applied. The press apparatus of the present invention comprises a main body 10, An upper punch 20 and a die 40 which are installed on the lower part of the punch driving part and the upper part of the die driving part and move up and down, and a die 40 are inserted into the molding hole 41 of the die 40 A lower punch 30 which presses the powder material together with the upper punch 20 and a lower punch 30 which is horizontally movable on one side of the middle part of the main body 10 and which is provided inside the molding hole 41 of the die 40 And a powder supply container 52 for supplying the powder material into the molding hole 41 of the powder feeder feeder 50. [

The punch driving unit and the die driving unit are for vertically driving the upper punch 20 and the die 40. The punch driving unit and the die driving unit directly connect the ball screws 120 and 120a to the servo motors 110 and 110a, So that the feeding speed and stroke of the upper punch 20 and the die 40 can be precisely controlled. The configuration and operation of the punch driver and the die driver will be described later in detail with reference to FIG. 3 to FIG.

The upper punch 20 is coupled to the lower end of the punch driving unit and moves up and down. The lower end of the upper punch 20 is inserted through the upper end of the molding hole 41 formed in the die 40, The powder material is pressed and formed together with the lower punch 30 inserted through the lower end of the hole 41.

The lower punch 30 is fixed to the main body 10 and an upper end is inserted into the molding hole 41 of the die 40.

The die 40 is fixedly installed at a central portion of a die plate 42 which is coupled to the die driving unit and moves up and down together with the die plate 42. At the center of the die 40, And a molding hole 41 is formed so as to penetrate vertically.

The powder feeder 50 is horizontally reciprocated laterally on the upper surface of the die 40 by a feeder driver 51 so as to supply the powder material to the inside of the molding hole 41 of the die 40 . The powder feeder 50 is connected to the powder supply container 52 through a hose 53 to guide the powder supplied from the powder supply container 52 into the shaping hole 41. The feeder driver 51 may be constructed using a hydraulic cylinder or a known linear motion device using a motor and a ball screw. The powder feeder 50 and the feeder driver 51 may be constructed by applying a known powder feeder and a driver, which are configured in a general powder molding press apparatus.

The punch driver is configured to move the upper punch 20 up and down at a predetermined speed and stroke. The die driver is configured to move the die plate 42 provided with the die 40 up and down at a predetermined speed and stroke.

3 and 4, the punch driving unit includes a servomotor 110 fixedly mounted on the upper portion of the press apparatus body 10, and a pawl driving unit 100 which is directly coupled to the center of the servomotor 110, A ball screw 120 connected to the ball screw 120 to move up and down by rotation of the ball screw 120 and coupled to the lower end of the upper punch 20 by a rotation of the ball screw 120, (RAM) 130, as shown in FIG.

A shaft support block 140 having a shaft insertion hole 141 through which the screw shaft 121 of the ball screw 120 passes is vertically provided below the servo motor 110, A bearing 145 for rotatably supporting the screw shaft 121 with respect to the shaft support block 140 is provided inside the shaft insertion hole 141 of the shaft support block 140.

The servomotor 110 includes a motor housing 111 having an opening through which a screw shaft 121 of the ball screw 120 passes, and a stator 120 installed inside the motor housing 111, A rotor 113 coupled to the screw shaft 121 and rotating within the motor housing 111 and an upper end portion of the screw shaft 121 at an upper end of the motor housing 111, And an encoder 115 for measuring the amount of rotation.

The stator 112 includes a core 112a disposed in a circumferential direction of the motor housing 111 and a coil 112b wound on the core 112a to receive power from the outside .

The rotor 113 has a hollow cylindrical shape and is coupled to one end of the screw shaft 121 and rotatably installed inside the stator 112. And a plurality of permanent magnets 113b provided along the circumferential direction on the outer surface of the permanent magnets 113a and 113a so as to be rotated by a magnetic field induced between the stator 112 and the permanent magnets 113b.

The ball screw 120 includes a screw shaft 121 having an upper end coupled to the center of the servo motor 110 and rotating with a screw groove formed in a spiral shape on an outer surface thereof, And a nut portion 122 that moves up and down along the axial direction of the screw shaft 121 by the rotation of the screw shaft 121 as the screw shaft 121 rotates.

(Not shown), a screw groove corresponding to the screw groove is formed in a spiral shape on the inner circumferential surface of the nut portion 122, and a screw groove (not shown) of the screw shaft 121 And a plurality of balls rolling along the screw groove are provided. Further, the nut 122 is coupled with the ram 130, which moves up and down with respect to the main body 10, so that rotation is restrained.

When the screw shaft 121 rotates, the ball of the nut 122 rolls along the screw groove of the screw shaft 121 and the nut 122 moves in the axial direction of the screw shaft 121, As shown in FIG.

The screw shaft 121 of the ball screw 120 has an elongated circular bar shape and is coupled to the rotor 113 of the servomotor 110 through an opening at the center of the lower surface of the motor housing 111, do. The screw shaft 121 is inserted into the central portion of the servomotor 110 and connected to the rotor 113 of the servo motor 110. The screw shaft 121 includes a motor coupling portion 121a, A rotation support portion 121b extending from the rotation support portion 121b and extending from the rotation support portion 121b to be supported by the bearing 145 while passing through the shaft support block 140, And a nut driving part 121c having a screw groove to which the part 122 is coupled is formed in a spiral shape.

The ram 130 is configured to linearly reciprocate up and down along a guide bush 133 installed in the ram housing 132 of the main body 10 in a vertical direction, 122, and reciprocates vertically together with the nut portion 122.

The lower end of the ram 130 is provided with a punch holder 135 to which the upper punch 20 is coupled.

As shown in FIG. 5, the die driving unit has substantially the same configuration as that of the punch driving unit at the lower portion of the main body 10. That is, the die driving unit includes a lower ball screw 120a inserted into the center of the lower servo motor 110a and a lower ball screw 120a coupled to the nut 122 of the lower servo motor 110a, And a shaft support block 140a and a bearing 145a for rotatably supporting the lower ball screw 120a from the upper side of the lower servo motor 110a And a die holder 135a to which the die plate 42 is coupled is installed at an upper end of the lower ram 130a.

The construction of the lower servo motor 110a and the lower ball screw 120a of the die driving unit is substantially the same as that of the servo motor 110 and the ball screw 120 of the punch driving unit, and thus a detailed description thereof will be omitted.

The operation of the press apparatus according to the present invention will now be described.

The powder feeder 50 is disposed outside the die 40 and the lower punch 30 is inserted inside the molding hole 41 of the die 40 and the upper punch 20 is inserted into the die 40 The powder feeder 50 is slid along the upper surface of the die plate 42 by the operation of the feeder driver 51 so that the powder feeder 50 Is moved to the upper side of the die 40.

The lower servomotor 110a of the die drive unit operates to raise the nut 122 and the lower ram 130a of the lower ball screw 120a by a predetermined distance to raise the die plate 42. [ At this time, the die plate 42 rises to a height such that the upper end of the lower punch 30 does not fall outside the lower end portion of the molding hole 41 of the die 40.

In this state, the powder material is fed to the powder feeder 50 through the powder feed container 52 and the powder material is fed into the inside of the molding hole 41 of the die 40 by receiving the guidance of the powder feeder 50 do.

When the powder material is filled in the molding hole 41 of the die 40, the powder feeder 50 slides in the outward direction of the die 40, as opposed to the former, and the molding hole 41 of the die 40 To be exposed to the outside.

Subsequently, the servomotor 110 of the punch driving unit is operated so that the nut portion 122 and the ram 130 are lowered to a certain distance and the upper punch 20 is inserted through the upper opening of the molding hole 41, And pressurized downward. Thus, the powder material in the molding hole 41 is compacted by the upper punch 20 and the lower punch 30 to form a green compact.

The servo motor 110 of the punch driving unit is operated in reverse to move the upper punch 20 upward to come out of the molding hole 41 and the lower servo motor 110a of the die driving unit operates in reverse So that the die 40 is lowered.

The green compact placed on the upper end of the lower punch 30 is protruded to the outside of the molding hole 41 as the die 40 is lowered so that the operator or the molded green compact can be separated from the die 40 . Thus, one cycle of the molding process is completed, and the above-described operation is repeatedly and repeatedly performed to produce the green compact.

As described above, the powder molding press apparatus of the present invention includes servo motors 110 and 110a as drive devices for driving the upper punch 20 and the die 40, The combined ball screws 120 and 120a constitute the speed and distance control of the upper punch 20 and the die 40 with high accuracy.

Particularly, the rotor 113 of the servomotors 110 and 110a constituting the punch driving unit and the die driving unit of the press apparatus of the present invention is constituted by a hollow body having an empty central portion and the screw shaft 121 of the ball screws 120 and 120a The upper punch 20 or the die 40 can be moved up and down so that the rotational force of the rotor 113 can be reliably transmitted to the ball screw 120 And 120a can be more precisely controlled.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention as defined by the appended claims. And it is to be understood that such modified embodiments belong to the scope of protection of the present invention defined by the appended claims.

10: main body 20: upper punch
30: Lower punch 40: Die
41: molding hole 42: die plate
50: powder feeder 51: feeder driver
52: Powder supply container 53: Hose
110: Servo motor 111: Motor housing
112: stator 112a: core
112b: coil 113: rotor
113a: Lotus pool 113b: permanent magnet
115: encoder 120: ball screw
121: screw shaft 122: nut part
130: ram 135: punch holder
135a: die holder 140: axis support block

Claims (5)

A body 10;
A die 40 mounted vertically movably in the main body 10 and having a molding hole 41 through which the powder material to be molded is injected;
A lower punch 30 fixed to the main body 10 at a lower side of the die 40 and inserted through a lower portion of the molding hole 41 of the die 40;
And an upper punch 20 which is installed on the upper side of the die 40 so as to be movable upward and downward and presses the powder material together with the lower punch 30 while being inserted through the upper part of the molding hole 41 of the die 40 )Wow;
A punch driving unit and a die driving unit installed on the upper and lower portions of the main body 10 to move the upper punch 20 and the die 40 up and down;
A powder supply unit for supplying the powder material into the molding hole 41 of the die 40;
/ RTI >
Wherein the punch driver and the die driver include:
A servo motor 110 and 110a fixed to the upper and lower portions of the main body 10;
A screw shaft 121 whose one end is coupled to the center of the servomotors 110 and 110a and which has a screw groove formed in a spiral shape on the outer surface thereof and a screw shaft 121 coupled to the outer surface of the screw shaft 121, A ball screw (120, 120a) having a nut portion (122) that moves up and down along the axial direction of the screw shaft (121) by the rotation of the screw shaft (121) as the screw shaft (121) rotates;
A ram 130, 130a coupled to the outside of the nut portion 122 and vertically moving together with the nut portion 122 and coupled to a die into which a punch or a powder material is inserted, );
And a pressing member for pressing the pressing member. The apparatus according to claim 1, further comprising: an axis support block (140, 140a) fixed to the main body (10) and having a shaft insertion hole (141) through which the screw shaft (121) Bearings 145 and 145a provided inside the shaft insertion holes 141 of the shaft support blocks 140 and 140a and rotatably supporting the screw shaft 121 with respect to the shaft support blocks 140 and 140a And a pressurizing unit for pressurizing the powder. The motorcycle according to claim 2, wherein the screw shaft (121) comprises a motor engaging portion (121a) inserted into a central portion of the servomotors (110, 110a) and engaged with a rotor (113) of the servomotors (110, A rotation support portion 121b extending from the motor coupling portion 121a in the axial direction and supported by the bearings 145 and 145a while passing through the shaft support blocks 140 and 140a, And a nut driving part (121c) formed to extend in the axial direction from the outer circumferential surface (121b) and having an outer surface formed with a screw groove to which the nut part (122) is coupled. The servo motor according to claim 1 or 3, wherein the servomotors (110, 110a)
A motor housing (111) having an opening through which the screw shaft (121) passes, in a central portion of an upper surface or a lower surface;
A stator 112 including a core 112a disposed in a circumferential direction inside the motor housing 111 and a coil 112b wound on the core 112a and receiving power from the outside;
A lotus core 113a which is hollow and has a hollow cylindrical shape and is engaged with one end of the screw shaft 121 and is rotatably installed inside the stator 112; And a rotor (113) rotating by a magnetic field induced between the stator (112) and the permanent magnet (113b), including a plurality of permanent magnets (113b) Press apparatus. The servo motor according to claim 4, wherein an encoder (115) is provided at one end of the motor housing (111) of the servomotors (110, 110a) for measuring the amount of rotation by being engaged with one end of the screw shaft (121) Wherein the press machine is a press machine for driving a servo motor.

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